Electrical batteries are used in a wide variety of applications requiring a portable power source. For example, portable devices such as laptops, tablets, mobile phones, portable flashlights, wristwatches, smoke detectors, vehicles, hearing aids and other medical devices, communications radios, light emitting devices, sound systems, night vision goggles, and even portable battery recharging units require a portable power source so that the devices may be used while they are in a portable mode. Some devices may be engineered to include a connected housing for a battery, such that the battery can be transported as an integral component of the device. Others devices may be engineered so that the battery can be carried separately, with interfaces to be plugged into a separately carried battery. These separately carried batteries may then serve as a power source for any variety of devices that have the appropriate interface for drawing electricity from the battery.